In vehicles such as automobiles or trucks, a multitude of information from various applications of the vehicle is typically displayed on a display device of the vehicle having a graphic display. The display device often has a touch-sensitive surface, which is superimposed on the display area of the display device in order to permit operator control of the various applications. Frequently, it is desirable and/or advantageous if outputs from two different applications are displayed on the display device. For example, an output from a navigation system may be output on one subarea of the display device, while information of an audio system, for instance, or a data management system that makes address data, so-called contact data, available may be output on another subarea of the display device. The result of a permanent division of the display area of the display device into a plurality of subareas is that only a small display area in one subarea of the display device is available for an application. Therefore, it is desirable to be able to dynamically split the display area of the display device in an easy manner into subareas for several applications.
In this connection, U.S. Patent Application Publication No. 2007/0222769 describes a display device in which a touch-detection section detects the location on a display screen where a user finger is touching the display screen. A transfer-length calculation section calculates the transfer length of the user's finger from the touch start location to the touch end location. A transfer-length judgment section judges whether or not the transfer length is greater than a reference transfer length. A shift calculation section calculates the shift of the user's finger. A shift judgment section judges whether or not the shift is less then a predetermined reference shift. If the transfer length is greater than the reference transfer length and the shift is less than the reference shift, a screen-split control section controls the operation of an image display section in such a way that the display screen is split.
If, when using the display device described in U.S. Patent Application Publication No. 2007/0222769, additional operating elements are represented on the display device which are able to be actuated by the user by touching them, it is possible that the gesture for dividing the screen may not be able to be distinguished clearly from an operating gesture, and thus the screen may be divided or an operating element may be actuated unintentionally.